JPH03439Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to the structure of a sewerage manhole provided on a water-permeable paved road surface.

(Prior Art) Recently, in many urban areas, the surface layer of paved roads has been roughened to allow rainwater to penetrate underground. This is to prevent flooding of rivers and the death of roadside trees due to large amounts of rainwater being collected in sewers during rainy weather. On such permeable pavement surfaces, a large amount of rainwater permeates into the ground, which tends to cause the ground to become soft. When the ground becomes soft, it adversely affects the stability of buried objects on the permeable pavement surface.

(Problems to be solved by the invention) As for the above-mentioned negative effects on buried objects due to the weakening of the ground, the greater the weight of the buried objects, the greater the concern about their stability. For example, there is concern about ground subsidence near sewer manholes. In addition, a lot of rainwater from the road surface collects around the manhole and tends to flow underground, and some of it flows into the porous sewage pipe (separate type) connected to the manhole. When rainwater enters sewage pipes, the processing burden on sewage treatment plants increases accordingly, so it is necessary to prevent rainwater from entering sewage pipes as much as possible.

The present invention has been made in view of the above points, and aims to provide a manhole structure that prevents the weakening of the ground due to rainwater collecting around the manhole.

(Means for solving the problem) In order to achieve this purpose, the means of the present invention is to drill a large number of small holes in the wall of the manhole so that rainwater that permeates underground along the outer periphery of the manhole can be The device is characterized in that it is configured to be introduced into the manhole through the small hole.

To form a small hole in a manhole, when making a manhole in a factory or on-site, a hollow member corresponding to the small hole is placed in a predetermined position, connected and fixed to the manhole formwork, and concrete is poured. It is established by inserting. In principle, small holes should be provided uniformly distributed throughout the manhole wall, but should be provided at least a certain distance apart near the attachment point of the footrest.

The subject of this invention is a sewer manhole buried in a permeable road surface, but it is applicable not only to those made of reinforced concrete but also to those made of unreinforced concrete. Rainwater flowing into the manhole from the small hole is sent to a sewer pipe exclusively for rainwater or to a sewer pipe for overflow-type wastewater and rainwater.

When rainwater flows into a small hole, there is a concern that underground particles may enter the small hole along with the rainwater and cause clogging, but in order to prevent this, it is necessary to install a filter around the manhole. All you have to do is backfill the sand or gravel layer.

(Function) The manhole structure of the present invention has a large number of small holes in the wall. For this reason, when rainwater that falls on permeable pavement permeates into the ground and some of it collects around the manhole, much of this rainwater flows into the manhole through the small holes and falls to the bottom of the manhole. The water then flows through the sewer pipes. Therefore, the amount of rainwater flowing deeply into the manhole ground is reduced accordingly, and the weakening of the manhole ground due to rainwater is prevented. Furthermore, since most of the rainwater around the manhole flows into the manhole, the amount of rainwater that permeates towards the sewage pipes is greatly reduced, and rainwater is prevented from being sent to the sewage treatment plant as much as possible.

(Example) An example of the present invention will be described below based on the drawings.

In Fig. 1, 1 is a water-permeable paved road surface, 2 is a sewer manhole buried in the paved road surface 1, and a rainwater pipe 3 is located at the bottom of the manhole 2.
is connected. This manhole 2 is made of water-permeable reinforced concrete, and its surroundings are compacted by a sandy stratum that has a filter effect. A large number of small holes 4 are arranged in almost the entire area of the wall of the manhole 2. In this embodiment, the diameter of the small holes 4 is in the range of 12 to 18 mm, more preferably 15 mm, and the distance between adjacent small holes 4 is
The range is 80 to 120 mm, more preferably 100 mm.

Therefore, rainwater that seeps into the road surface 1 and collects on the circumferential surface of the manhole 2 on a rainy day flows into the manhole 2 through the small hole 4. At that time, fine earth and sand may enter the small holes 4 due to the flow of rainwater. To prevent this, each small hole 4 is fitted with a cylindrical wire mesh filter 5 having an inclined bottom surface 5a, as shown in FIG. Note that in FIG. 1, illustration of the wire mesh filter 5 is omitted. In this case, in order to prevent the filter 5 from coming off, it is recommended to provide a protrusion 6 on either the outer surface of the filter 5 or the inner surface of the small hole 4, and a recess 7 that rotatably engages with the protrusion 6 on the other. desirable. By connecting adjacent filters 5, 5 to each other with a string or the like, each filter 5 can be prevented from falling and being lost, making handling extremely convenient.

FIG. 3 shows a modification of the inner surface structure of the small hole 4.
An inclined portion 8 that slopes downward toward the opening end is provided on the bottom surface near the inflow side opening of the small hole 4 made of pipe material 12, and a U-shaped engaged member 9 is provided at the outflow side opening of the small hole 4. and attach a circular filter 10 to it.
is attached in a sliding manner. However, the filter 10 is provided with an engaging piece 11 that fits into the engaged member 9 from above (see FIG. 4). In addition, if a recess is formed in the upper part of the small hole 4 on the inlet side, as shown by reference numeral 4a in FIG. 5, rainwater can be guided into the manhole more actively. The filter 9 can also be configured to be provided on the inlet side of the small hole 4.

(Effects of the invention) As described above, according to the invention, rainwater that has permeated around the sewerage manhole in the basement of a permeable road surface actively flows into the manhole through the small hole. Softening of the ground near the manhole can be effectively prevented. In addition, it is possible to prevent rainwater from penetrating into the porous wastewater pipe disposed near the manhole as much as possible. Therefore, it is possible to prevent a large amount of rainwater from being sent to the sewage treatment plant through the sewage pipes, especially during heavy rain, and its practical value is extremely great.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view of a manhole according to the present invention, Fig. 2 is a cross-sectional perspective view of a main part showing a cylindrical filter according to the embodiment installed, and Fig. 3 shows a circular filter installed. 4th sectional view of main parts showing
This figure is a right side view of FIG. 3 showing the circular filter in a detached state, and FIG. 5 is an enlarged view showing a modification of the inlet side portion of the small hole. 1... Permeable pavement surface, 2... Manhole, 4
...small hole, 5,10...filter.

Claims (1)

[Scope of utility model registration request] On the wall of a manhole buried in a permeable road surface,
A manhole structure characterized by a large number of small holes for introducing water.